EU's Tusk says 'some progress but lot needs to be done' in UK talks

EU president Donald Tusk warned on Friday that more work was needed to reach a deal at a leaders' summit in Brussels to keep Britain in the EU.

"For now I can only say that we have made some progress but a lot needs to be done," Tusk told a brief press conference at the end of the first day of the meeting.

Spanish Prime Minister Mariano Rajoy meanwhile said he was optimistic about the chances of a deal.

"I think it is going well. I hope that tomorrow we will have a deal," he told reporters.

Tusk and European Commission President Jean-Claude Juncker immediately went into a face-to-face meeting with David Cameron on the British prime minister's reform demands.

Former Polish premier Tusk was also due to meet French President Francois Hollande, Belgian Prime Minister Charles Michel and Czech Prime Minister Bohuslav Sobotka.

Hollande has reservations about Cameron's demands for safeguards for countries that do not use the euro currency, while Michel objects to calls to exclude Britain from the EU's goal of "ever closer union".

The Czech premier meanwhile leads a group of four Eastern European countries that object to Cameron's request for a limit to welfare benefit payments for EU migrants working in Britain.